But if educational differentials and assortative mating lie behind much of the gap between those in loudoun county and poorer americans , they do not explain the hamptons phenomenon .
Many social transformations are also making inequality worse , particularly the rise of single parenthood and " assortative mating " ( the tendency of educated people to marry each other ) .
Belot and francesconi discovered that a strong social trend towards " assortative mating " means that although educated , high-achieving men are not interested in marrying a rich woman , they do like educated high-achieving women , rather than shallow girls with shiny nails .